2cups All purpose flour
1cup Corn flour
2cups Sugar
4nos Eggs
1cup Yogurt
1cup Canola oil
1tsp Vanilla extract
150grms Dark chocolate bar
1tsp Baking powder
1/4tsp Baking soda
Mix together the all purpose flour,corn flour, baking powder and baking soda and keep aside..Beat together the eggs and sugar until it turns pale and smooth, now add the yogurt and oil ,beat everything again for a while..now add the flours , stir everything well and dont overmix..Meanwhile melt the chocolate bar with few water in microwave oven for 4minutes, divide the already prepared batter in two bowls, to the one bowl add the vanilla extract and mix it while in another bowl add the melted chocolate and mix it..Preheat the oven to 350F..
Greased a round pan or loaf pan, pour the vanilla flavoured batter first, then pour the chocolate batter, with a knife make some swirls through the batter to marbleize it..Bake for 25-30minutes in middle rack or until a toothpick inserted in the centre comes out clean..keep aside and let them cool, springle some powdered sugar over the cake before serving..
Serve warm or at room temperature..